Conventionally, metal materials of W, Cu, and the like have been mainly used for contact portions electrically connecting a functional element of a transistor or the like and a wiring, via portions electrically connecting wirings at a position above a functional element, and further, TSVs electrically connecting three-dimensionally stacked semiconductor chips, and the like. Nowadays, as an alternative to the above-described metal materials, a carbon-based material such as carbon nanotubes (CNTs) is drawing an attention. The CNT is regarded as a promising material having a low resistivity, a high current density resistance, and a high thermal conductivity.
Patent Document 1: Japanese Laid-open Patent Publication No. 2007-26839